100g ground almonds (1 cup plus 2 TBS plus 2 1/2 tsp)

For the sponge:

110g of butter diced (7 TBS plus 2 tsp)

150g of caster sugar (3/4 cup)

4 medium free range eggs

150g dessicated coconut (scant 2 cups)

75g ground almonds (14 TBS)

1 tsp baking powder, sifted

110g of sultanas (3/4 cup)

Icing sugar to dust

Have ready a 9 by 13 inch non-stick baking pan.  I line it with baking paper leaving an overhang so I can lift them out once cooled.  Butter the paper.

Place all of the ingredients for the base in a food processor.   Blitz to make crumbs, then keep the motor running until the mixture comes into a ball, scraping down the sides a couple times.   The dough will be soft and sticky.   Press the dough into the base of the baking tin.  Cover with a piece of cling film and smooth it out.  Chill in the refrigerator for one hour.

Preheat the oven to 160*C/325*F/ gas mark 3.  Prick the base all over with a fork.  Bake for 25 to 30 minutes until the base is just beginning to colour.   Stir the jam with a fork to loosen it.  Spread the jam in a thin layer over the base using a palate knife.  Increase the oven temperature to 190*C/375*F/ gas mark 5.

Place the butter and sugar into a bowl.  Cream together until well blended.  Beat in the eggs, one at a time.   Whisk in the coconut, ground almonds, baking powder and the sultanas.   Spoon the sponge mixture over top of the jam, spreading it into an even layer.   Bake for 25 to 30 minutes, until the sponge has set and the top is golden brown.   Run a knife carefully around the edges of the cake in the tin while it is still hot, then leave to cool completely. 

Lift out onto a board and then cut into two long slices through the middle and then cut each half into 8 slices.  Dust with icing sugar to serve.